THE PRESENT INVENTION relates to a safety arrangement, and more particularly relates to a safety arrangement in a motor vehicle.
It has been proposed to provide a motor vehicle with an accelerometer adapted to provide a signal indicative of the acceleration being experienced by a central part of the vehicle, that signal, or its integrated valve, being used to control the activation of a safety device, such as an air-bag. A problem with an arrangement of this type is that the accelerometer is not able to distinguish sufficiently quickly between impacts of different degrees of severity. The accelerometer can only respond to the deceleration of the central part of the motor vehicle which is separated from the point of impact by a "crumple zone". Thus the deceleration experienced by the central part of the vehicle or its integrated valve may be substantially the same at the time when the safety device has to be triggered, regardless of the degree of severity of the impact.
Whilst an accelerometer provided at the front of the vehicle would be able to distinguish between impacts of different severity sufficiently quickly, there would be a grave risk that a front-mounted accelerometer would be substantially damaged during an impact and thus would not prove to be reliable.